#include <iostream>

using namespace std;

class User{
private:
    string account;
    string password;
    string email;
public:
    User(string account,string password,string email="")
    {
        this->account = account;
        this->password = password;
        this->email = email;
    }
        string showInformation(){
            return "账号:" + account + ",密码:" + password + ",邮箱:" + email;
        }
    };
int main()
{
    User user1("123","abc","123abc@qq.com");
    User user2("456","def");
    cout <<user1.showInformation()<<endl;
    cout <<user2.showInformation()<<endl;
    return 0;
}
